A water stop switch device includes: a main body, a transmission element and a sealing element; the main body is disposed with a water passage, the sealing element is disposed in the water passage; one end of the sealing element is coupled to the transmission element in transmission way, the sealing element moves in the water passage to open the water passage; the other end of the sealing element and the main body surround to form a chamber; the side wall of the sealing element is disposed with a through hole connecting the water passage and the chamber; when the water passage is open, the chamber is full of water to reduce the pressure difference at two ends of the sealing element.